Cost-effectiveness of a fixed combination of hydroquinone/tretinoin/fluocinolone cream compared with hydroquinone alone in the treatment of melasma

Journal of Drugs in Dermatology, Feb, 2007 by Tania Cestari, Lucie Adjadj, Margaret Hux, Maria Regina Shimizu, Vincent Pierre Rives

There are several important methodological considerations for this study. Although effectiveness and resource use from a study conducted in Brazil were used to estimate cost-effectiveness in a number of countries where the TCT is available, effectiveness of treatment obtained from within a clinical trial protocol with fixed treatment and assessment is expected to be transferable across countries. Even though the study was open label, it is the best information available on patients randomized to treatments and given careful standardized assessments. Furthermore, generalizing treatment effect across countries is supported by a large study that found TCT cream to be effective for patients with a range of skin types and racial origins presenting with melasma. (30)

Melasma-related cost for this analysis has been calculated including only the melasma treatment products used since the clinical trial did not collect other melasma treatments during or after the study, nor resources to treat adverse effects related to the prescribed drugs. Although this definition for health economic analyses is much more limited than usual, the medication price is the key driver of total cost, and so a valid estimate of cost. Other primary concurrent melasma treatments are the use of sun block and moisturizers, and since patients in both groups should be using these it is assumed that this would make no difference to an incremental comparison. Comparison of adverse events considered potentially related to study medication found pruritus increased with HQ and desquamation increased with TCT. For each of these conditions, clinical input indicated that signs of these adverse events might appear early in the treatment and treatment response would likely be use of moisturizers and possibly temporary treatment interruption. Since most patients would be using moisturizers and sun block agents in any case, and early treatment discontinuation would be reflected in the costs presented, not including these costs is not expected to affect the evaluation. Cost for subsequent melasma treatments for patients who fail the initial therapy would also be relevant as some patients who do not have clearing of the melasma might consider other treatment options such as chemical peels or microdermabrasion with substantial associated costs. Since many more TCT patients showed complete clearing, not including this cost is expected to be conservative for the evaluation of TCT.

Since topical creams for the treatment of melasma are purchased on a per package basis, the total cost will include wastage. Packaging size and the number of tubes required for the average usage of each treatment observed in the clinical trial was found to be a key factor influencing the results. An alternate analysis, calculating cost in each country based on the number of tubes for the most appropriate available size, found that whether the average usage observed in the trial fell just above or below the tube size had a substantial effect on cost-effectiveness. This estimate is provided as a sensitivity analysis.